Distribution of Endangered Turtle Species in Maine

http://digitalcommons.colby.edu/atlasofmaine2009/1019/thumbnail.jpg

Pressure Perturbation Calorimetry and Guest-Host Chemistry of NDMG and N-MAP with p-Sulfonatocalix[6]arene

The aim of this project is to provide an explanation for recently obtained binding constants for two similar guest molecules, NDMG and N-MAP, with a p-sulfonatocalix[6]arene host in ammonium acetate buffer. This work was done primarily using pressure perturbation calorimetry, which is a technique that determines the coefficient of thermal expansion, α, which is in turn related to the solute molecule's effect on the order of the surrounding water molecules. A series of experiments were designed to test the effects of suspected confounding variables on the validity of PPC data. PPC was then used to study NDMG and N-MAP in ammonium acetate buffer. NDMG exhibited a minimum in α as function of temperature, while N-MAP did not. This difference was theorized to be due to the formation of an intramolecular hydrogen bond in monocationic NDMG that would lower the heat capacity of the molecule and better distribute the molecule's charge. Computational work and nuclear magnetic resonance spectroscopy confirmed that monocationic, ring-closed NDMG has less concentrated charge and more constrained motion than monocationic, ring-open NDMG. This evidence supports the theory that monocationic NDMG forms an intramolecular hydrogen bond and that this may be responsible for the minimum in α. This difference may explain the differences in binding constants between NDMG and N-MAP.

Characterization of the 4.5S RNA molecule in Escherichia coli

The 4.5S RNA molecule of Escherichia coli is essential to cell viability. It has been shown that depletion of this molecule inhibits protein synthesis, induces the heat shock response, and generally slows cell growth. The molecule has also been implicated in protein secretion, as in cells depleted of 4.5S RNA, an unsecreted precursor to ?-lactamase accumulates (pre-?-lactamase). A role in protein secretion is further supported by structural similarities with the 7S RNA molecule of eukaryotic SRP, specific binding to SRP54, and its homolog in E. coli, P48, and the ability of 7S RNA from certain archaebacteria to suppress 4.5S RNA depletion. In this study I have utilized strains with mutant forms of the 4.5S RNA genes in order to study the effect of altered 4.5S RNA on cell physiology. These strains have their mutant 4.55 RNA under the control of the tryptophan synthetic operon. Decreased growth rates, inhibited cell division, and altered protein synthesis all result from these mutations.

Oxford movement: its themes and their significance

In retrospective, the Oxford movement of nineteenth century England provides one with an interesting study of the struggles between the spiritual and secular worlds. However, repeated abstraction in an interpretation of its significance has tended to distort accurate understanding of its historical development. Often this also has resulted n a misinterpretation of the nature of its major themes and their significance to the world. For these reasons, this study has attempted to describe the origin, maturity, and dissolution of the series of events which strictly speaking may be considered to be the Oxford movement. In conclusion, liberty has been taken to comment on the nature of the Movement's themes and their significance in their own age and to man today.

Crown ethers : applications in inorganic synthesis

The ability of macroheterocyclic compounds to complex with ionic species has led to the synthesis and investigation of many multidentate macroheterocyclic species. The most stable complexes are formed between macrocyclic polyetheral ligands (crown ethers) with alkali or alkaline earth metal iona. There is an excellent correlation of the stability of these complexes with the size of the cation and the site of the cavity in the macrocyclic ligand. Additional factors, such as the basicity of the ligand and the solvating ability of the solvent, also play important roles in the stabilization of the complex. The stability of such complexes has been advantageously used to increase anionic reactivity and has been successfully applied to several organic fluorinations, oxidations, and similar reactions. The use of macrocyclic ligands in inorganic syntheses of otherwise difficult to obtain fluoro compounds has not been reported. O-carborane and m-carborane, C2BlOHl2, are icosahedral cage systems derived from Bl2H122- by replacement of BH with the isoelectronic CH group. These stable molecules exhibit electron-deficient bonding which can best be explained by delocalization of electrons. This delocalization gives rise to stability similar to that found in aromatic hydrocarbons. Crown ether activated potassium fluoride has been successfully employed in the conversion of alkyl, acyl and aryl halides to their respective fluorides. Analogously halide substituted carboranes were prepared, but their fluoro-derivatives were not obtained. The application of crown ethers in the synthesis of transition metal complexes is relatively unexplored. The usual synthesis of fluoro-derivative transition metal complexes involves highly reactive and toxic fluorinating agents such as antimony trifluoride, antimony penta fluoride. bromine trifluoride and hydrogen fluoride, An attempted preparation of the hexafluoroosmate (IV) ion via a crown activated, or naked fluoride~was unsuccessful. Potassium hexafluoroosmate (IV), K208F6. was eventually prepared using bromine trifluoride as a fluorinating and oxidizing agent .

Power outage, and other poems

Contents - At the Starry Night Cafe AIbino Buffalo Monteverdi In The Rain Lust Litter Poem After The Chinese Cleere's Pub Treasure Island Nipple Periwinkle Talkeetna Beached Whale Spending Christmas in the land of Enchantment Easter Poem For Emily Dickinson Second Hand Gifts The Power Outage October In The Observation Car Westerly

The Econometric Value of Silence and Noise as Seen by a Non-practicing Marxist

A Collection of Poetry and Fiction

Just which Reality do you Mean? Users' Experiences of Virtual Spaces

Virtual Reality is a relatively new technology in the relatively young field of computer science. The design of Virtual Reality has only recently come into discussion, as well as the implications for this sort of design. I hope to determine how a user can work most efficiently and accurately in a Virtual World. By studying this, I hope to help in the standardization of Virtual Reality design.

Use of microprojectile bombardment in transient expression assays to analyze protochlorophyllide reductase gene expression in greening maize seedling leaf cells

In young cells of leaf meristems the progenitors of chloroplasts are small organelles known as proplastids, which divide and differentiate into chloroplasts. However, in the absence of light, proplastids undergo a different sequence of development and become etioplasts. When light is supplied to etiolated plants during the "greening" process, etioplasts differentiate into chloroplasts containing chlorophyll. An important light dependent step in chlorophyll biosynthesis is the photoreduction of protochlorophyllide to chlorophyllide by the NADPH:protochlorophyllide reductase (PCR) enzyme. This enzyme is present at high activity only in etiolated tissue and during early stages of light-induced chlorophyll synthesis. The enzyme and its corresponding mRNAs decrease dramatically with prolonged exposure to light. We have investigated the light-dependent transcriptional regulation of a PCR gene in greening maize leaf cells using a transient expression assay based on microprojectile bombardment. The promoter region was isolated and cloned into a ?-glucuronidase (GUS) reporter gene expression plasmid. We have used this chimeric plasmid in tungsten particle bombardment of both etiolated and greening maize seedling leaves to determine whether the cloned promoter region contains regulatory sequences that control light-responsive PCR gene expression.

Grotesque in Dickens

Dickens's use of the grotesque in his novels undergoes a variety of changes. For convenience sake, and to better illustrate the developments of the grotesque, I divide the novels into three separate groups. The first group, the period of experiment, included the novels from Pickwick Papers through Barnaby Rudge; the second group, the period of transition, includes the novels from Martin Chuzzlewit through David Copperfield; and the third, the period of a new vision. included the novels from Bleak House through Edwin Drood. Basically, I see the development of the grotesque involving a change in Dickens's conceptions of society, as well as responding to complex changes in society itself; Dickens's vision loses much of its humor in the end, yet it also reflects a definite maturity.

Constructing a Structural Macroeconomic Model Using Multiple Techniques

This project constructs a structural model of the United States Economy. This task is tackled in two separate ways: first econometric methods and then using a neural network, both with a structure that mimics the structure of the U.S. economy. The structural model tracks the performance of U.S. GDP rather well in a dynamic simulation, with an average error of just over 1 percent. The neural network performed well, but suffered from some theoretical, as well as some implementation issues.

Exploration of the idea of the horse in graphics and sculpture

The exploration of the idea of the horse is a very complex and open quest. Primarily it entails some conception of what the idea of the horse is. In choosing to title the project as such, I was attempting to indicate that what was of major interest to me was the representation of those qualities of the horse which are abstract and intangible as well as the physical qualities of the horse. Because of this interest, much of my work is concerned with movement, gesture, and the effects of structure, or lack thereof, on movement and gesture.